Disposable absorbent articles, such as disposable diapers, have heretofore conventionally been constructed utilizing a fluid permeable top sheet for being positioned in contact with the wearer for receiving and passing therethrough body fluids, a fluid impermeable bottom sheet positioned away from the wearer for preventing the body fluids of the wearer from passing out of the article and an absorbent pad positioned between the top sheet and the bottom sheet for absorbing the body fluids of the wearer.
Examples of such disposable diaper constructions may be seen in U.S. Pat. No. 3,636,952, issued Jan. 25, 1972, and U.S. Pat. No. 3,951,151, issued Apr. 20, 1976, both of which are assigned to the assignee of the present invention. Processes and apparatus for producing these types of disposable diapers may be seen in U.S. Pat. No. Re 28,139, reissued Aug. 27, 1974 and U.S. Pat. No. 3,984,272, issued Oct. 5, 1976, both of which are assigned to the assignee of the present invention.
As may be seen in these process and apparatus patents, and more particularly in U.S. Pat. No. 3,857,657, issued Dec. 31, 1974, assigned to the assignee of the present invention, the absorbent interior pads for these disposable articles or disposable diapers are conventionally produced by fiberizing a wet-pressed sheet of cellulosic fibers with a "licker-in" type fiberizing means and air laying the fibers to form a batt or pad of individual fiberized fibers. This fiberizing and air-laying mechanism and operation may be utilized directly in the diaper fabricating apparatus and process or it may be separately utilized for forming fiberized fiber batts or pads. Other types of apparatus including "hammer mill" type devices have also been utilized for fiberizing of wet-pressed wood pulp sheets into individual fibers for batts or pads in disposable absorbent articles.
To aid in fiberizing of the wet-pressed cellulosic fiber sheets, which are normally produced by paper manufacturers and provided to disposable articles fabricators, it has heretofore been suggested to utilize or treat the wet-pressed wood pulp sheets and fibers therein with a cationic debonding agent for purposes of aiding in the fiberizing operation and to obtain an air-laid batt or pad of fibers after fiberizing which is substantially completely fiberized and which does not have undesirable residual sheet particles therein, broken fibers and dust, so as to provide greater height and loft to the resulting fiberized fiber batt or pad. Such treatment of fibers during production of a wet-pressed cellulosic fiber sheet with a cationic debonding agent is disclosed in U.S. Pat. No. Re. 26,939, reissued Aug. 18, 1970, U.S. Pat. No. 3,554,862, issued Jan. 12, 1971 and U.S. Pat. No. 3,554,863, issued Jan. 12, 1971, all of which are assigned to the assignee of the present invention.
Although the apparatus, processes and resulting disposable diaper products and fiberized fiber absorbent pads of the above-mentioned prior patents of the assignee of the present invention have been satisfactory and commercially successful to the assignee of the present invention, it has been found that certain problems did exist with respect to providing a top surface on the absorbent pad which would be drier to the wearer of the disposable absorbent article and with respect to wicking and spreading of the body fluids within the absorbent pad away from the top surface of the absorbent pad.